Next: Acknowledgements Up: Knowledge-Based B-Factor Restraints for Previous: Example Refinement
Next: Acknowledgements
Up: Knowledge-Based
B-Factor Restraints for Previous: Example
Refinement
A new formulation is described for restraining the B-factors of low to moderate resolution protein models based on stereochemistry. The procedure can be implemented simply and requires very little additional computation. It permits B-factors to have the variability observed in reliably-determined structures but damps the fluctuations caused by the limited diffraction data.
The procedure is intended for cases where the diffraction data are limited to resolution of about 2Å or less. It could be used at higher resolution although the present restraint library is limited by the resolution of the reference protein structures (1.6 - 1.7Å) and the small sample size.
The restraints and the overall procedure are currently available in the TNT refinement package [Tronrud et al., 1987] for the refinement of proteins. A further survey including nucleic acids and common enzyme co-factors still needs to be done.